I Lost The Product Key For Microsoft Math What Do I Do? Where Can I Get Another Product Key?

Unfortunately you cannot get another key. The manufacturers at Microsoft do not keep records and they will tell you this if you call they're hotline

Well probably you could search the torrents sites for so-called "Free" downloads of Microsoft Math that carry along with them trojans; but then that wouldn't be legal and besides, your computer could start behaving strangely thanks to this one move of yours...